As similar to Blue diamonds, one of the most rarest natural fancy color diamonds Gray diamonds are also being created due to an exposion to the hydrogen element, nitrogen or boron during the diamond's formation process. Gray diamonds are frequently can be found in the following geographical regions: South Africa, India, Russia, Brazil and Australia. The famous Argyle mine which is located in the Kimberly region in western Australia actually produces Gray diamonds as well which are constitute 2% from the total mine's production. Most of the Blue-Gray Argyle mine diamonds are classified as type Ia, meaning they are carrying a large concentrations of hydrogen and nitrogen defects.
Gray diamond's color will be grade on a scale of light (smoke) Gray to dark (graphite) Gray, but in most cases the Gray color will appear as a secondary color modifier to Blue diamonds or Green diamonds. As appose to other natural colour diamonds Gray diamonds do not have a huge demand, there for their prices consider to be low, comparable even to colorless diamonds with same carat weigh, clarity and other similar identifiers.